The 6.6 magnitude quake struck in Lushan county, near the city of Ya'an in the southwestern province of Sichuan, at a depth of 7.5 miles, close to where a devastating 7.9 temblor hit in May 2008 killing some 70,000.

Most of the deaths were concentrated in Lushan, a short drive up the valley from Ya'an, but rescuers' access was hampered by the narrowness of the road and landslides.

"The Lushan county centre is getting back to normal, but the need is still considerable in terms of shelter and materials," said Kevin Xia of the International Federation of Red Cross and Red Crescent Societies.

"Supplies have had difficulty getting into the region because of the traffic jams. Most of our supplies are still on the way," Xia said.

Pictures on state television showed toppled buildings and people in bloodied bandages being treated in tents outside the Lushan hospital. Water and electricity in the area were cut off by the quake.

Premier Li Keqiang flew into the disaster zone by helicopter to voice support for the rescue operation.

Chen Yong, the vice director of the Ya'an city government earthquake response office, told reporters that the death toll was unlikely to rise by much more.

"We understand the situation in most areas. Most of the casualties have been reported. In some remote mountain areas, it is possible that we don't fully understand the situation," he said.

Schools withstand quakeBut no schools had collapsed, unlike in 2008 when many schools crumpled causing huge public anger, prompting a nationwide campaign of re-building.

"Our schools are the safest and sturdiest buildings," Chen said. "The Chinese government has put a lot of money into building schools and hospitals. I can guarantee that no schools collapsed."

Xinhua said 6,000 troops were in the area to help with rescue efforts.

Rescuers in Lushan had pulled 91 survivors out of rubble, Xinhua said. In villages closest to the epicenter, almost all low-rise buildings had collapsed, footage on state television showed.

The China Meteorological Association warned of the possibility of landslides in Lushan county, with more than 1,000 aftershocks registered.

Ya'an is a city of 1.5 million people and is considered one of the birthplaces of Chinese tea culture. It is also the home to one of China's main centers for protecting the giant panda.

Sichuan is one of the four major natural gas-producing provinces in China, and its output accounts for about 14 percent of the nation's total.

Sinopec Group, Asia's largest oil refiner, said its huge Puguang gas field was unaffected.

The U.S. Geological Survey initially put the magnitude at 7, but later revised it down.

In 2010, a 7.1 magnitude earthquake killed 2,700 people in Yushu, a largely Tibetan region in northwest China.